On Thursday afternoon, more than 1,500 students will gather at Watertown High School to welcome first lady Michelle Obama at the launch of a nationwide campaign to get Americans to drink more water.

"Who would not be interested in meeting any first lady of the United States?" said Watertown schools Superintendent Cassandra Schug. "I just think this is a once-in-a-lifetime opportunity for our students."

Obama, through her "Let's Move!" initiative, and the Partnership for a Healthier America are bringing together a coalition from industry, entertainment, media and government to get behind the campaign.

The tagline of the campaign is deceptively simple — Drink Up.

But backers of the campaign are clearly trying to thread a needle by promoting water without casting a negative light on other beverages, including soda and juice drinks.

They're also dealing with a political environment in which boosters of healthy initiatives are sometimes accused of fostering a "nanny state."

A release from Michelle Obama's office said that according to the Centers for Disease Control and Prevention, "More than 40% of Americans drink less than half of the recommended amount of water daily, and approximately one-fourth of children don't drink any water on any given day."

Sam Kass, the executive director of Let's Move!, said: "Our core messages are that drinking more water is the fastest and easiest choice that we can make every day. ...Water is the original energy drink. This is a really exciting, fun and very positive campaign that is really going to inspire people to drink more water."

Kass said the first lady and her team are excited to come to Watertown, using it as s symbol for other towns across the country.

Obama will be joined by actress Eva Longoria.

Lawrence Soler, president and CEO of the Partnership for a Healthier America, listed nearly two dozen water brands that have signed on to the initiative, as well as the American Beverage Association and the International Bottled Water Association. Municipal water services are also on board.

"Every participating company has agreed to only encourage people to drink water, not focus on what people should drink. Not even talk about why they feel their type of water is better than another," Soler said.

The campaign will be rolled out on online and on television, from the morning shows such as the "Today" show and "Good Morning America" to the late night broadcasts including the "The Tonight Show with Jay Leno" and the "Late Show with David Letterman."

Wis-Pak, a manufacturer of Pepsi-Cola and other soft drinks, is also on board. The firm employs 200 people at its Watertown bottling facility.

Barbara Parish, president of Wis-Pak, said the company is pleased that Obama chose Watertown to launch the initiative. Wis-Pak bottles Aquafina and has lines of flavored waters, juices and teas.

"Wis-Pak has been part of the Watertown community for over 40 years and we are proud of the jobs and economic contributions provided to the area over that period of time," she said in a statement.

Even the Rusty Nail, a local bar, was getting into the spirit of the event.

A sign outside the bar read: "Michelle and Eva, 2 for 1 water and Desperate Housewife Reruns. Noon to Close."

The other side of the sign read: "Save Water. Drink Beer."

About Bill Glauber

Bill Glauber is a general assignment reporter, focusing on profiles and politics.